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Toggle Switch Question

Started by Timko, May 08, 2015, 08:49:44 AM

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Timko

I'm about to start building the Bear Hug Compressor (http://1776effects.com/wp-content/uploads/2015/03/Bear-Hug-V2-1.pdf), and the BOM called for an On/Off SPST toggle switch.  When I placed my order with SmallBear, they only had SPDT switches.  Here's the one I got:

http://www.mammothelectronics.com/electonic-switches-s/21.htm

Since the SPDT has 3 lugs instead of 2, and the Bear Hug PCB only has points to wire 2, I think what I need to do is wire lug 2 and lug 3 to the board, and leave lug one alone.  Based on the schematic that's in the first link, the switch is only enabling a resistor in the signal path or disabling it.  It's not a switch that selects between 2 things.

Could someone let me know if I'm on the right track?

HamSandwich

Exactly. All you want to do is make or break a connection. Wire one of the pads to the center/common, the other two one of the lugs, doesn't really matter. When the toggle is slanted away from the outer lug, the connection will be made. When it's slanted towards the connected lug, the connection is broken.

Timko


Timko

I saw another pedal build document for another pedal that also used a SPDT switch that had lug one wired to the board, and lugs 2 and 3 connected then wired to the board.  Is there any difference with that scheme?  It seems to me to be the same (in the first case, there's an input and an output, and in the 2nd case, one of them is missing).  Is there a reason to do one over the other?

HamSandwich

I don't see any reason to connect the center and normally empty outer lugs together since you're getting the same exact function.  :o